Diabetes is a very common disease that develops when the body does not produce enough, or appreciably any, insulin or cannot properly use or respond to insulin. There are two major types of diabetes. Type 1 diabetes is also known as insulin-dependent diabetes mellitus (IDDM) and results from insufficient insulin production. The onset of Type 1 diabetes occurs most often in children, adolescents, or young adults and is regarded as an autoimmune disease. Type 2 diabetes is known as noninsulin-dependent diabetes mellitus (NIDDM) and is the most common form of the disease, accounting for about 90% of all cases of diabetes. In many cases. Type 2 diabetes, in the initial phases, is characterized by a suboptimal response to insulin. Although insulin is produced, the ability of a given amount of insulin needed to effect a given decrease in blood glucose is increased. In Type 2, patients manifest a blunted blood glucose response to insulin, i.e., a state of insulin resistance. The causes of diabetes are not completely known, although both genetic and environmental factors, such as obesity and lack of exercise, increase the risk. There is also a form of diabetes that may develop during pregnancy (gestational diabetes), and a form of autoimmune diabetes that develops in adulthood, which is called latent autoimmune diabetes in adults (LADA) or slowly progressing autoimmune diabetes.
Type 1 diabetes is treated with insulin, although other treatments have been proposed and transplantation of insulin-producing islet cells from the pancreas has been tested. Non-pharmaceutical intervention is usually prescribed initially for Type 2 diabetes (e.g., diet modification, weight loss, and exercise). If this is not successful, patients are then generally treated with one of three different types of drugs: drugs that stimulate the release of insulin from the pancreas; drugs that increase a patient's sensitivity to insulin; and drugs that directly affect the circulating levels of glucose (e.g., drugs that decrease the production of glucose from the liver or increase its uptake by muscles). More specifically, a patient may be prescribed a sulfonylurea, an α-glucosidase inhibitor, metformin (GLUCOPHAGE™), or troglitazone (REZULIN™). In many cases, insulin is also used. After many years of living with type 2 diabetes, some patients manifest exhaustion of the insulin producing apparatus and thereby require insulin therapy.
Despite the progress in understanding and treating diabetes, none of the current treatment strategies are optimal, and there is a great need for better ways to treat patients who have diabetes or who are at risk of developing diabetes.